1. Field of the Invention
This invention relates to a process for production of hydrogen from oil shale fines. The process provides high conversion of the organic carbonaceous material in oil shale to hydrogen for a wide variety of uses. In one embodiment, the hydrogen and product gases produced by the process of this invention are particularly useful in the hydroretorting and hydrogasification of oil shale to produce useful liquid and gaseous products. The process of this invention provides efficient utilization of substantially the entire amount of organic carbon in mined oil shale.
2. Description of the Prior Art
There is a recognized need for hydrogen in a wide variety of chemical processes. The process of this invention provides hydrogen for such processes and particularly advantageously provides increased efficiency in the utilization of oil shale in the production of liquid and gaseous fuels from carbonaceous materials such as oil shales.
Processes for hydrogasification of oil shales are disclosed in U.S. Pat. Nos. 3,891,403 and 3,929 615. U.S. Pat. No. 3,703,052 teaches hydrogasification of shale oil to produce pipeline quality gas wherein shale fines and spent shale with coke from the hydrogasifier are gasified in a steam-oxygen gasifier at 1500.degree.-2100.degree. F. and preferably 1600.degree.-1900.degree. F. to favor direct formation of methane and conversion of the gaseous mixture to a hydrogen-rich gas by a carbon monoxide shift reaction or by a steam-iron process and the solids recirculated to the hydrogasifier. U.S. Pat. No. 3,708,269 teaches hydrogasification of fluid fossil fuels and mixtures of fluid and solid fossil fuels to produce synthetic pipeline gas wherein spent solids from the hydrogasifier are gasified in a steam-oxygen gasifier to favor direct formation of methane and the gas mixture treated by a carbon monoxide shift reaction and purified to produce hydrogen-rich gas for hydrogasification and the solids recirculated to the hydrogasifier. One of the unexpected features of the present invention is the large amount of direct hydrogen formation from shale fines at lower temperatures.
Hydroretorting of oil shale to produce hydrocarbon liquids likewise uses a large amount of hydrogen as taught by U.S. Pat. Nos. 3,922,215; 4,003,821; and 4,075,081. U.S. Pat. No. 3,577,338 teaches a method for oil production from oil shale which simultaneously produces hydrogen as a by-product by passing oil shale through a combustion zone in a retort while continuously introducing steam and oxygen into the combustion zone. U.S. Pat. No. 4,010,092 teaches combusting spent coke containing shale in a steam-oxygen mixture resulting in steam-rich water gas for use in the oil shale retorting-gasification process. U.S. Pat. No. 4,001,105 teaches catalytic hydrocracking of carbonaceous materials using activated spent shale and forming hydrogen for the reaction in situ. The present invention does not depend upon catalytic properties of shale inorganic matrix, which may vary substantially from one shale to another.